The best alternative fuel

Biodiesel is good; conservation is better

Growing enough crops to meet the demand for biofuels could endanger the worlds remaining forests and open space.

PHOTO COURTESY OF GETTY IMAGES

Untitled Document
What are the environmental pros and cons of switching
to plant-based “biofuels” to reduce our reliance on oil? Because ethanol and biodiesel are derived from
agricultural crops, they are inherently renewable, and ethanol and
biodiesel emit less particulate pollution than traditional petroleum-based
gasoline and diesel fuels. They also do not contribute to global warming,
because they only emit back to the environment the carbon dioxide that
their source plants absorbed from the atmosphere in the first place. And unlike other forms of renewable energy (such as
hydrogen, solar, and wind), biofuels can be used without making major
changes to vehicles or homes — just fill your existing car, truck, or
home oil tank with the alternative fuel. Those looking to replace gasoline with ethanol in
their cars, however, must have a “flex-fuel” model that can run
on either fuel. Otherwise, most regular diesel engines can handle biodiesel
as readily as regular diesel. Despite the upside, however, experts note that
biofuels are far from a cure for our addiction to petroleum. A wholesale
societal shift from gasoline to biofuels, given the number of gas-only cars
already on the road and the lack of ethanol or biodiesel pumps at existing
filling stations, would take some time. Another major hurdle for the widespread adoption of
biofuels is the challenge of growing enough crops to meet demand, something
skeptics say might well require converting just about all of the
world’s remaining forests and open spaces over to agricultural land.
“Replacing only 5 percent of the nation’s
diesel consumption with biodiesel would require diverting approximately 60
percent of today’s soy crops to biodiesel production,” says
Matthew Brown, an energy consultant and former energy program director at
the National Conference of State Legislatures. “That’s bad news
for tofu lovers.”Another dark cloud looming over biofuels is whether
producing them actually requires more energy than they can generate. After
factoring in the energy needed to grow crops and then convert them into
biofuels, Cornell University researcher David Pimental concludes that the
numbers just don’t add up. His 2005 study found that producing
ethanol from corn required 29 percent more energy than the end product
itself is capable of generating. He found similarly troubling numbers in
making biodiesel from soybeans. “There is just no energy benefit to
using plant biomass for liquid fuel,” says Pimentel. There is no one quick fix for weaning ourselves off
fossil fuels, and the future will likely see a combination of sources
— from wind and ocean currents to hydrogen, solar and, yes, some use
of biofuels — powering our energy needs. The “elephant in the
living room,” however, that is often ignored when energy options are
considered is the hard reality that we must reduce our consumption, not
just replace it with something else. Indeed, conservation is probably the largest single
“alternative fuel” available to us. For more information:
Ecology Center Biofuel Factsheet,
www.ecologycenter.org/factsheets/-biodiesel.html; Earth911 Energy
Conservation Factsheet,www.earth911.org/master.asp?s=lib&a=
Energy/energy.asp. Send questions to Earth Talk, care of E/The Environmental Magazine,
P.O. Box 5098, Westport, CT 06881 or e-mail earthtalk@emagazine.com.